Modern heavy-duty gas turbines are equipped with multi-burner silo-combustors, with annular combustors or with can-annular combustor arrangements.
A can-annular combustor consists of a number of individual can-combustors, annularly arranged in the combustion chamber of the gas turbine. The design of a conventional can-combustor is characterized by having a cylindrical combustor with—at its upstream end—one center burner and more than five burners arranged in an annular pattern equally spaced at a constant radial distance to the central axis of the circular combustor. The center burner can be of different design and can have a different axial exit plane position in relation to the other burners. The center burner often works as a pilot stage featuring part of the fuel being injected in a diffusion flame mode or as a partially premixed pilot.
A combustor of this type is disclosed, for example, in the published patent applications DE 102010060363 or in DE 102011000589.
WO 2012136787 discloses a can-annular combustion system in connection with a heavy-duty gas turbine using the reheat combustion principle.